KRASNODAR, July 7 (RAPSI) – Sergei Tsapok, a crime group boss who was sentenced to life for the murder of 12 people in southern Russia, died on the night of July 6 at a detention facility, RIA Novosti learned at the Investigative Committee’s Kuban Department.

Tsapok was tentatively diagnosed with a stroke on July 5. However, the press service of the Federal Penitentiary Service said that Sergei Tsapok died of acute heart failure.

Three members of Tsapok’s criminal group have recently committed suicide at detention facilities. One of the group’s principal hit men who received a life sentence, Igor Chernykh, hanged himself last Friday.

On November 4, 2010, 12 people, including four children, were brutally murdered in the village of Kushchevskaya in the Krasnodar Territory in southern Russia. The family of wealthy local farmer Server Ametov was stabbed to death along with visiting friends and a bystander. The convicted killers started several fires around the house before fleeing.

That murder became one of the most high-profile cases in modern Russia. The investigation revealed that the thugs had terrorized the village for years, and that some local police officers had covered up their activities.